I had a recent experience with my new dell laptop that I wanted to share to save others the pain. I installed Office 2019 and on my wired connection my emails were connecting and up/downloading without a problem. Then I moved rooms and connected to wireless. Emails stopped flowing and I received the error "0x800ccc0f". Emails worked fine on my phone on wireless and the wireless was assigned to the same firewall profile as my wired adapter.

I pulled my hair out for a while before I remembered all the additional software Dell had loaded on my system. I disabled everything that wasn't Microsoft and long story short ... it was Rivet SmartBytes stopping my email. Re-starting only that service stopped my email again. I have now uninstalled it but wonder why Dell install it if it causes these kinds of issues.

I hope this saves someone else some time as all other sites I found on this error said check your firewall. I didnt think SmartBytes was firewall software so it took me a bit to get there.